foldr1 package:rio

foldr1 is a variant of foldr that has no starting value argument, and thus must be applied to non-empty ByteStrings

foldr1 is a variant of foldr that has no starting value argument, and thus must be applied to non-empty ByteStrings An exception will be thrown in the case of an empty ByteString.

A variant of foldr that has no base case, and thus may only be applied to non-empty structures. This function is non-total and will raise a runtime exception if the structure happens to be empty.

Examples

Basic usage:

>>> foldr1 (+) [1..4]
10

>>> foldr1 (+) []
Exception: Prelude.foldr1: empty list

>>> foldr1 (+) Nothing
*** Exception: foldr1: empty structure

>>> foldr1 (-) [1..4]
-2

>>> foldr1 (&&) [True, False, True, True]
False

>>> foldr1 (||) [False, False, True, True]
True

>>> foldr1 (+) [1..]
* Hangs forever *

O(n) A variant of foldr that has no starting value argument, and thus must be applied to a non-empty Text.

foldr1' is a variant of foldr1, but is strict in the accumulator.

A variant of bifoldr that has no base case, and thus may only be applied to non-empty structures.

Examples

Basic usage:

>>> bifoldr1 (+) (5, 7)
12

>>> bifoldr1 (+) (Right 7)
7

>>> bifoldr1 (+) (Left 5)
5

> bifoldr1 (+) (BiList [1, 2] [3, 4])
10 -- 1 + (2 + (3 + 4))

>>> bifoldr1 (+) (BiList [1, 2] [])
3

On empty structures, this function throws an exception:

>>> bifoldr1 (+) (BiList [] [])
*** Exception: bifoldr1: empty structure
...